How RNA Editing Helped Animals and Fungi Adapt, Innovate, and Thrive Through Evolutionary Challenges

What is it about?

This study explores A-to-I RNA editing, a unique process in living organisms where subtle modifications are made to genetic instructions for protein synthesis. This process, which has independently evolved in both animals and fungi, enables organisms to adapt to environmental challenges. The researchers propose that A-to-I editing resolves genetic "trade-offs," situations where a beneficial change in one area can inadvertently cause problems elsewhere. In animals, A-to-I editing may have initially emerged as a mechanism to balance growth and development with defense against harmful genetic elements, such as transposable elements, during the evolution of multicellularity. Subsequent major environmental shifts, including the cooling during the Late Devonian period and the warming during the End-Permian period, may have driven the increased utilization of A-to-I editing. For instance, it may have facilitated the development of complex nervous systems and intelligence in animals like squids and octopuses, as well as the loss of their shells. In fungi, this process might have contributed to the development of their reproductive structures. In conclusion, the study indicates that A-to-I RNA editing has significantly contributed to the evolution of unique traits and environmental adaptation in both animals and fungi, potentially accelerating development and supporting diverse survival strategies.

Featured Image

Photo by Raimond Klavins on Unsplash

Photo by Raimond Klavins on Unsplash

Why is it important?

This work is unique and timely because it proposes novel adaptive hypotheses for the origins and phenotypic significance of A-to-I RNA editing, moving beyond mechanistic descriptions to explore why this process evolved. It posits that A-to-I editing alleviates genetic trade-offs, allowing for flexible responses to environmental challenges, and links its emergence in specific lineages (coleoids and Sordariomycetes) to major environmental events (Late Devonian cooling and End-Permian warming). Crucially, the paper connects A-to-I editing to key evolutionary innovations like metazoan nervous system evolution, coleoid intelligence/shell loss, and fungal sexual reproduction, suggesting it facilitated these transitions. Finally, it proposes a role for editing in accelerating development and shaping life-history strategies, offering a broad, cross-kingdom perspective that is timely given the growing interest in RNA editing and its contribution to phenotypic diversity and adaptation in a changing world.

Perspectives